Downey Jr plays Tony Stark in the franchise, with his father in the Marvel universe, Howard Stark, portrayed by Dominic Cooper in Captain America.

Samuel L Jackson plays Nick Fury in the Iron Man films, a role which he reprised for Thor, Captain America and forthcoming film The Avengers.

Other stars in attendance last night included High School Musical actress Vanessa Hudgens , who took to the red carpet in a loose-fitting gold dress with platform heels, and Avatarâs Zoe Saldana, who kept it casual with matching shorts and jacket.

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Captain America is released in the US this Friday, making its UK debut on July 29.